Headcase

Thoughts on the mind.

No Harm, No Foul

How the brain forgives murder.

The Headcase was away last week and didn't have a chance to post on these items. But I intended to post—information I share in the wake of a very interesting new study showing the importance of intention on moral judgment.

Up to age six, research has shown, children judge an act based largely on its outcome. If Little Larry is knocked down by Tiny Tommy and scrapes his knee, the preschool crowd is likely to view as Tommy "naughty," whether the collision was intentional or not.

As we grow older and our brains develop, we begin to place more weight on intent when judging harmful actions. With this in mind, a team of cognitive scientists from M.I.T. and Harvard—not exactly lightweights—examined a region of the brain known as the right temporo-parietal junction (RTPJ), previously linked with moral consideration. In the current report, published in PNAS, the researchers not only confirm the RTPJ's role in processing moral intention, but also found it quite susceptible to manipulation.

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The scientists presented people with a variety of hypothetical murder scenarios. As Science NOW reports, some scenarios described a person who killing someone accidentally, while others told of a person who intended to kill but failed. The test participants then rated the killer's conduct on a moral scale.

During the tests, the researchers occasionally disabled the RTPJ of test subjects through transcranial magnetic stimulation. In general, study participants considered those who intended to kill as less morally forgivable than those who did so by accident. When the RTPJ was disabled, however, people became more forgiving of those who tried but failed to kill, by roughly 15 percent.

In short, the authors conclude, without the ability to process intention, people relied more heavily than usual on the end result—say, whether or not the victim died—when judging a harmful act:

Disrupting RTPJ activity has the selective effort of causing participants to judge attempted harms as more morally permissible than they would normally. ... When activity in the RTPJ is disrupted, participants' moral judgments shift toward a "no harm, no foul" mentality.

The study sparks several lines of interesting thought. We like to believe age brings us wisdom, but the research suggests, at least to The Headcase, that much of our wisdom is the result not of experience but of developed brains. There's a Little Larry lurking in us all, then. Or, as Bob says, "Oh my name it ain't nothing, my age it means less." (Brief Bob digression: The lack of "ain't" at this link brought to mind John Roberts's famous grammatical adjustment of a Dylan line.)

The findings also have obvious relevance to jury selection. For the moment, of course, this relevance is far more philosophical than practical. I've done enough research into lie detection to know that we're many years removed from using such technology in courtrooms, if we ever do. No judge (one hopes) would allow defense lawyers to disable certain parts of a juror's brain during verdict deliberations. But is it too far-fetched to conceive of a day when the size of a person's RTPJ renders him unfit for jury service, just as a defendant's mental fitness can render him unfit to understand the charges against them? If so, would that truly be a jury of one's peers, or simply a jury that scientists consider best fit to judge morality?

Which leads me to the true moral: When they make this movie starring Tom Cruise, I accept cash or check.

(HT to Liane Young, lead author, for sending The Headcase this paper.)(Image: Alvara Pascual-Leone; (inset)Liane Young)

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Follow me on twitter: e_jaffe

Science writer Eric Jaffe has covered behavior for several years and is working on a book about psychiatry during World War II.

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